Access to OS functions from CAPL

Question

I'm doing a script using CAPL and am stuck for a solution to grep the login ID from Windows. Could some please help show how to get Windows user login ID from within a CAPL program code, if this is possible?

For example, if the Windows user login ID is 'kp21ml' , I want to read this ID from a CAPL function, as shown below.

byte UserIdCheck()
{
  char uid[10];
  byte CanMessageTrasmission;

  strncpy(uid, xxxx(), 6);    // where xxxx() is the unknown OS or system function that could return the login ID ?
  if (strncmp(uid, "kp21ml") != 0)
  {
    write("Access denied!");   // Message to CANoe's Write window
    CanMessageTrasmission = 0;
  }
  else
  {
    // Access ok
    CanMessageTrasmission = 1;
  }

  return CanMessageTrasmission;
}

I use this CAPL book as my reference guide, which is very good: http://docplayer.net/15013371-Programming-with-capl.html But I couldn't find anything to do with system access. I would appreciate your help.

Thanks Juno

schaazzz · Answer 1 · 2016-12-19T14:54:59.950

I'm afraid you won't be able to do that directly from a CAPL script.

I generally create a CAPL-DLL and include that in my CANoe project when I need to access some OS level functionality. Though I use it mostly for accessing an external device (e.g. USB) or to interact with another program using sockets over local host, the principle is the same.

You can find more information in CANoe's documentation with examples but the CAPL-DLL source code provided in CANoe samples is a little difficult to understand.

I've attempted to strip some of the "unnecessary" parts in the following code sample; this example will create a CAPL-DLL which "exposes" the multiplyBy10 function and basically allows you to call multiplyBy10 from you CAPL script):

#define USECDLL_FEATURE
#define _BUILDNODELAYERDLL

#pragma warning( disable : 4786 )

#include "cdll.h"

#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <map>

char        moduleName[_MAX_FNAME];
HINSTANCE   moduleHandle;

unsigned int
CAPLEXPORT far CAPLPASCAL multiplyBy10 (unsigned char value)
{
    unsigned int result = value * 10;
    freopen("CONOUT$", "w", stdout);
    std::cout << "multiplyBy10() - value: " << int(value) << ", result: " << result << std::endl;
    return (result);
}    

CAPL_DLL_INFO4 table[] = 
{
    {CDLL_VERSION_NAME, (CAPL_FARCALL)CDLL_VERSION, "", "", CAPL_DLL_CDECL, 0xABD, CDLL_EXPORT},
    {"multiplyBy10", (CAPL_FARCALL)multiplyBy10, "CAPL_DLL", "This is a demo function", 'L', 1, "D", "", { "value"}},
    {0, 0}
};

CAPLEXPORT CAPL_DLL_INFO4 far * caplDllTable4 = table;

bool
WINAPI DllMain(HINSTANCE handle, DWORD reason, void*)
{     
    static FILE * stream;

    switch (reason) 
    {
        case DLL_PROCESS_ATTACH:
        {
            moduleHandle = handle;

            char path_buffer[_MAX_PATH];
            DWORD result = GetModuleFileName(moduleHandle, path_buffer, _MAX_PATH);

            char drive[_MAX_DRIVE];
            char dir[_MAX_DIR];
            char fname[_MAX_FNAME];
            char ext[_MAX_EXT];

            _splitpath_s(path_buffer, drive, dir, fname, ext);
            strcpy_s(moduleName, fname);

            AllocConsole();
            freopen_s(&stream, "conout$", "w", stdout);
            std::cout << "DLL_PROCESS_ATTACH" << std::endl;

            return 1;
        }

        case DLL_PROCESS_DETACH:                                              
        {
            std::cout << "DLL_PROCESS_DETACH" << std::endl;
            FreeConsole();
            fclose(stream);

            return 1;
        }
    }

    return 1;
}

Access to OS functions from CAPL

1 Answers1